Had I seen the question at the time I would have predicted a nasty outcome with a high level of certainty though my state my mind would have made me not care at all about it. I really couldn't give a shit about anything at the time.
Fair enough, at least you're not kidding yourself thinking it's safe and a good idea. I can understand being too addicted to care.
One thing's for sure, I won't be IV'ing ethylphenidate again.
I'm very glad to hear this!! I really hope that decision lasts. Good for you

. But please let us know if you ever decide to do it again and we will help to to find other options to avoid injecting into your neck.
I had become very dehydrated but was totally unaware.
For future reference, if you do decide to IV again, make sure you're really hydrated. Veins shrink up if you are dehydrated. And of course in general it's very important to stay hydrated.
Learn how to feel for veins.
Not at all savvy regarding this.
It can be learned. They feel different than the surrounding tissues. The best phlebotomists all use this method. You can find invisible veins this way. It also helps if you know where to look, hence the vein maps. Veins feel kind of like spongy noodles.
NOTE: I'm certainly NOT trying to encourage you to try IVing again, it sounds like you've done a lot of damage already and I think stopping is necessary, I'm just providing this info in case you do end up doing it again, or for anyone else reading who may be wondering how to find alternatives to the jugular.
I prefer a fresh needle but will use up to 3 times depending on vein and whether there is noticeable resistance on attempting the subsequent shot. A twice used needle that glides in on the third try is fine by me but any resistance means immediate replacement.
I would seriously use a fresh needle for every single puncture, even if you've only used it to try to hit and weren't able to register. It does a lot to save you from destroying your veins and is imperative for people who already have wrecked veins and trouble hitting. See the image tricomb posted.
I often find when using the vacuum method that I can push the needle in to the point where the needle depth is clearly well beyond the depth of the vein but on careful withdrawal of the needle I get a week, brief flash when most of the needle has already been withdrawn, suggesting that I must have gone right through the vein without it registering. This has not been an uncommon occurrence.
This has happened to me when using veins that are really damaged or too tiny. IME if I only got a weak brief flash of blood, I would miss, or if I kept fishing around in the same spot I would just get tiny flashes which would fill up the syringe with blood and have no luck getting a proper register.
Were you inserting the needle like this? At a 15 to 45 degree angle, bevel facing up? (of course the exact angle is going to vary from vein to vein, but you can see from this diagram why this would normally work best)
If you've damaged all your veins that quickly you should not be IVing. And if the only vein you have left to IV with is your neck it's time to quit.
I totally agree. Something that caustic to the veins is really not worth injecting IMO. It took me a lot longer to destroy all my veins, but once I did they were so messed up that to this day even experienced hospital staff can't hit them. I shudder to think what could have happened if I had kept going and destroyed my jugular as well.